1. Field of the Invention
The present invention relates to a liquid crystal display panel, a pixel array substrate and a pixel structure thereof.
2. Description of the Prior Art
Generally speaking, a liquid crystal display panel has advantages of light weight, low power consumption, and low radiation; therefore, the liquid crystal display panel has been widely applied to many kinds of portable electronic products in the market, such as notebooks and personal digital assistants (PDA). When the liquid crystal display panel is driven, if liquid crystal molecules are fixed at an angle for a long time, the liquid crystal molecules may have the permanent deformation, so that frames displayed by the liquid crystal display panel cannot be changed. For this reason, a polarity inversion driving method is used to prevent from lowering the display quality of the liquid crystal display panel.
The polarity inversion driving method usually is divided into a frame inversion, a row inversion, a column inversion and a dot inversion. Please refer to FIG. 1. FIG. 1 illustrates a schematic diagram of a polarity arrangement of sub-pixels with white vertical-striped pattern displayed by the liquid crystal display panel utilizing the dot inversion driving method according to the prior art. As shown in FIG. 1, the liquid crystal display panel 10 of the prior art has a plurality of sub-pixels 12 arranged as a matrix. The sub-pixels 12 in each column respectively display red, green, and blue sequentially, and furthermore, a red sub-pixel (12R), a green sub-pixel (12G) adjacent to the red sub-pixel, and a blue sub-pixel (12B) adjacent to the green sub-pixel constitute a pixel 18. When the liquid crystal display panel 10 is driven by the dot inversion driving method, the polarity arrangement of the sub-pixels 12 in a same row has a positive polarity 14 and a negative polarity 16 arranged alternatively in sequence, and so does the polarity arrangement of the sub-pixels 12 in a same column.
Moreover, when the liquid crystal display panel 10 is tested by displaying the white vertical-striped pattern, the pixels in the same row alternatively display bright and dark in sequence, and the pixels in the same column display bright or dark. In the dot inversion driving method, the red sub-pixels (12R) and the blue sub-pixels (12B) that are turned on and disposed in the first row have the positive polarity 14 and the green sub-pixels (12G) that are turned on and disposed in the first row have the negative polarity 16. The polarity of each sub-pixel 12 is determined by comparing a pixel voltage of each sub-pixel with a common voltage. This means that when the pixel voltage is higher than the common voltage, the polarity of the sub-pixel 12 is the positive polarity, and the pixel electrode is at a high level. On the contrary, when the pixel voltage is lower than the common voltage, the pixel electrode is at a low level and the polarity of the sub-pixel 12 is the negative polarity.
Please refer to FIG. 2. FIG. 2 illustrates a timing of a pixel voltage of the red sub-pixel/blue sub-pixel and a pixel voltage of the green sub-pixel in the first row of FIG. 1. As shown in FIG. 1 and FIG. 2, in the same row, when the number of sub-pixels 12 having the positive polarity 14 is more than the number of sub-pixels 12 having the negative polarity 16, i.e. the data signal Vd provided to the red sub-pixel (12R) and the blue sub-pixel (12B) is at the high-level, and the data signal Vd provided to the green sub-pixel (12G) is at the low-level, the common voltage Vcom is easily affected by the data signal Vd provided to the red sub-pixel (12R) and the blue sub-pixel (12B) to shift toward the high-level. For this reason, the voltage difference for driving the red sub-pixel (12R)/the blue sub-pixel (12B) is reduced, and the voltage difference for driving the green sub-pixel (12G) is increased. Furthermore, the gray scale displayed by the red sub-pixel (12R)/the blue sub-pixel (12B) is lower than the gray scale displayed by the green sub-pixel (12G). Therefore, when the liquid crystal display panel 10 of the prior art is driven by the dot inversion driving method to test the white vertical-striped pattern, the liquid crystal display panel 10 displays greenish frames. Thus, to solve the problem of greenish frame is an objective in industry.